4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 8a26f0f781f56d3016b34a2217e346973d067e7b ]
If a request is cancelled, we can't assume that the server returns 1 credit back. Instead we need to wait for a response and process the number of credits granted by the server.
Create a separate mid callback for cancelled request, parse the number of credits in a response buffer and add them to the client's credits. If the didn't get a response (no response buffer available) assume 0 credits granted. The latter most probably happens together with session reconnect, so the client's credits are adjusted anyway.
Signed-off-by: Pavel Shilovsky pshilov@microsoft.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cifs/cifsglob.h | 1 + fs/cifs/transport.c | 28 ++++++++++++++++++++++++++-- 2 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 38ab0fca49e1..7a4fae0dc566 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -1426,6 +1426,7 @@ struct mid_q_entry { int mid_state; /* wish this were enum but can not pass to wait_event */ unsigned int mid_flags; __le16 command; /* smb command code */ + unsigned int optype; /* operation type */ bool large_buf:1; /* if valid response, is pointer to large buf */ bool multiRsp:1; /* multiple trans2 responses for one request */ bool multiEnd:1; /* both received */ diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index d51064c1ba42..4dbf62bb51b2 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -785,6 +785,24 @@ cifs_noop_callback(struct mid_q_entry *mid) { }
+static void +cifs_cancelled_callback(struct mid_q_entry *mid) +{ + struct TCP_Server_Info *server = mid->server; + unsigned int optype = mid->optype; + unsigned int credits_received = 0; + + if (mid->mid_state == MID_RESPONSE_RECEIVED) { + if (mid->resp_buf) + credits_received = server->ops->get_credits(mid); + else + cifs_dbg(FYI, "Bad state for cancelled MID\n"); + } + + DeleteMidQEntry(mid); + add_credits(server, credits_received, optype); +} + int compound_send_recv(const unsigned int xid, struct cifs_ses *ses, const int flags, const int num_rqst, struct smb_rqst *rqst, @@ -860,6 +878,7 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses, }
midQ[i]->mid_state = MID_REQUEST_SUBMITTED; + midQ[i]->optype = optype; /* * We don't invoke the callback compounds unless it is the last * request. @@ -894,15 +913,20 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
for (i = 0; i < num_rqst; i++) { rc = wait_for_response(ses->server, midQ[i]); - if (rc != 0) { + if (rc != 0) + break; + } + if (rc != 0) { + for (; i < num_rqst; i++) { cifs_dbg(VFS, "Cancelling wait for mid %llu cmd: %d\n", midQ[i]->mid, le16_to_cpu(midQ[i]->command)); send_cancel(ses->server, &rqst[i], midQ[i]); spin_lock(&GlobalMid_Lock); if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) { midQ[i]->mid_flags |= MID_WAIT_CANCELLED; - midQ[i]->callback = DeleteMidQEntry; + midQ[i]->callback = cifs_cancelled_callback; cancelled_mid[i] = true; + credits[i] = 0; } spin_unlock(&GlobalMid_Lock); }